Event ID 90 — Network Adapter Functionality

Applies To: Windows Server 2008 R2

The network adapter to which Network Load Balancing (NLB) is bound must be properly configured and capable of performing NLB operations. If the adapter is not properly configured, the NLB driver may fail to bind to the adapter.

Event Details

Product: Windows Operating System
ID: 90
Source: Microsoft-Windows-NLB
Version: 6.1
Message: NLB cluster [%2]: The NLB driver failed to bind to the adapter because the maximum transfer unit (MTU) reported by the adapter is too small to contain an NLB heartbeat message. Ensure that the MTU of all hosts in the cluster is set to the default value.


Ensure that the MTU is properly configured

Ensure that the Maximum Transfer Unit (MTU) on the network adapters on all hosts in the Network Load Balancing (NLB) cluster is set to the default value or bind NLB to an adapter that supports a larger MTU.


When you are using nlb.exe, you must be a member of the Administrators group on the host that you are configuring, or you must have been delegated the appropriate authority. If you are configuring a cluster or host by running nlb.exe from a computer that is not part of the cluster, you do not have to be a member of the Administrators group on that computer.

To verify that the network adapters are properly configured:

  1. Open an elevated Command Prompt window. Click Start, point to All Programs, click Accessories, right-click Command Prompt, and then click Run as administrator.
  2. Type nlb.exe query, which displays the current cluster state and the list of host priorities for the current members of the cluster.
  3. Type nlb.exe display, which displays details on the current cluster configuration and the IP configuration on the host operating system and the network adapter. Verify the configuration of the network adapter.


Network Adapter Functionality

NLB Cluster